This invention relates generally to bottle caps and, more particularly, concerns the forming of indicia on such caps.
In the past, identifying or advertising indicia were emplaced on bottle cap top walls, as by printing. Inasmuch as printing adds to the cost of the cap, and requires extra handling, there is a need to eliminate printing but while somehow achieving indicia formation. Also, there has been a continuing need for method or means to retain bottle cap seals in position and against inadvertent removal.